Remote Monitor System with Radio Dispatch

ABSTRACT

The present invention is directed toward systems and methods for providing a remote monitoring system with radio dispatch. In an exemplary embodiment, the present invention provides a central monitoring unit for receiving a first event signal from a first remote monitoring device, identifying the first remote monitoring device as the originator of the first event signal, accessing a first prerecorded dispatch message associated with the first event signal, and transmitting the first prerecorded dispatch message. The present invention may also include multiple remote monitoring units for detecting events at a plurality of remote monitoring locations. Upon detection, the remote monitoring units transmit an event signal to the central monitoring unit.

CROSS-REFERENCE TO RELATED APPLICATION & PRIORITY CLAIM

This application is a continuation of U.S. Ser. No. 11/546,211, filed 11Nov. 2006 (to be issued on 30 Jun. 2009 as U.S. Pat. No. 7,554,439), theentire contents and substance of which are hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates generally to electronic monitoring systemsand more particularly to a remote monitoring system for detecting anevent condition and reporting such detection to a central system fortransmission of a radio dispatch message.

BACKGROUND OF THE INVENTION

Security guard forces have long been employed to patrol and protectproperty against unauthorized intrusion and vandalism. Such forces arecommon in large industrial complexes housing valuable equipment,inventory, or sensitive information. These complexes include, forexample, store rooms, computer rooms, warehouses, manufacturingfacilities, office buildings, military bases, department stores and thelike. Prior to the introduction of portable two-way radios, suchcomplexes would usually be patrolled by a team of guards with each guardperiodically patrolling a designated area of the complex and returningto a central station to report. Obviously, this left most areas of thecomplex unattended for long periods of time between patrols.

With the introduction of portable two-way radios, each guard of a teamcould be stationed permanently in his designated area and could reportin periodically to a central station via radio. He could also receiveinstructions via radio from the central dispatcher so that he could beadvised quickly and efficiently of a change in his assignment or of anunusual or threatening situation. While such a system is an improvementover roving patrols, it is still subject to numerous inherent problems.The guards, for example, being human, are subject to inattention and cansometimes be evaded by a clever intruder. This is particularly true insituations where little or no activity over long periods of time canlead to extreme boredom and fatigue among the guards. Probably the mostserious problem with posted human sentries is the extremely high cost insalaries and benefits of maintaining the necessarily large securityforce. Further, frequent turnover among security guards can lead to hightraining costs and reduced overall efficiency.

In recent years, electronic security systems have found widespread useas an adjunct to traditional radio dispatched security guard forces.Such systems can include passive infrared or heat sensors mounted indesignated areas of a guarded complex and positioned to detect thepresence of a person within the area. Upon such detection, the sensor,which is usually hard wired to a central control, signals the centralcontrol, which can emit a visual or audible signal indicating that anintruder has been detected.

Such security systems have allowed reduction in the number of personsrequired to guard a complex. Further, they are not subject to boredom,fatigue and evasion as human sentries can be. However, these motiondetecting security systems are relatively simple, are not generallyportable or easily adaptable to changing requirements, and convey nouseful information in addition to a simple signal that a detection hasbeen made. Accordingly, a guard responding to a detection must enter themonitored area with little or no information about where in the area theintruder was detected or how he may have been moving within the area.

The present inventor addressed these and other deficiencies in the artby providing an infrared sentry with voiced radio dispatched alarms, asdescribed in U.S. Pat. No. 5,283,549. This device broadcasts radiodispatch messages when an alarm is detected. While the solution providedan excellent solution at the time, additional challenges must beaddressed.

Over the past several years, police band radios have becomesignificantly more complex and expensive. Thus, the security units, eachof which includes a radio, have also become significantly moreexpensive. Therefore, many police departments are not able to buy thequantity of security units they desire due to budgetary constraints.

Additionally, numerous other industries desire to economically monitorbuildings and equipment in remote locations. For example, a informationtechnology support company tasked with maintaining server computerslocated at its customers' facilities, may desire notification if theserver is moved or overheats. Therefore, it would be desirable toprovide a system capable of monitoring such equipment and/or facilitiesand broadcasting an event message to personnel responsible formaintaining the equipment when necessary.

Accordingly, there is a need in the art for a low cost portablemonitoring system. Additionally, there is a need in the art for aportable monitoring system that does not require a dispatch radio to beinstalled in each remote unit. Further, there is a need in the art for amonitoring system in which a single radio device can service multipleremote monitoring stations. Further, there is a need in the art for amonitoring system that can receive event messages from a variety ofremote monitor devices and broadcast an event message.

SUMMARY OF THE INVENTION

The present invention is directed toward systems and methods forproviding a remote monitoring system with radio dispatch. In anexemplary embodiment, the present invention provides multiple remotemonitoring units for detecting events at a plurality of remotemonitoring locations. Upon detection, an event signal is transmittedfrom the remote monitoring unit to a central monitoring unit. Thecentral monitoring unit receives the event signal and broadcasts a radiodispatch message over a radio frequency.

In an exemplary embodiment, each remote monitoring unit is adapted todetect event conditions, such as alarms, intrusions, breakdowns, or thelike. Upon detection, the remote monitoring unit places a call to thecentral monitoring unit. The central monitoring unit receives the calland determines the origin of the call. The central monitoring unit maydetermine the origin of the call using DNIS data, or other means fordetermining where a call originated.

When the central monitoring unit determines where the call originated,it accesses a prerecorded message associated with the remote monitoringdevice that detected the event condition and broadcasts the associatedprerecorded message over a radio frequency. In an exemplary embodiment,the message is broadcast over a police-band radio.

These and other objects, features, and advantages of the presentinvention will become more apparent upon review of the followingdetailed description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary embodiment of thepresent invention.

FIG. 2 is a schematic block diagram illustrating preferredinterconnections of internal electronic components of the system toperform the method of the invention.

FIG. 3 is a flow diagram illustrating an exemplary method of receivingan event signal and broadcasting a dispatch message in accordance withan exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in more detail to the drawings, in which like numeralsrefer to like parts throughout the several views, FIG. 1 is a blockdiagram illustrating an exemplary embodiment of the present invention.As illustrated in FIG. 1, the present invention may include multipleremote monitoring units 11, 12 for detecting events at a plurality ofremote monitoring locations. Upon detection, an event signal istransmitted from the remote monitoring unit 11 to a central monitoringunit 10. The event signal may be transmitted over any availablecommunication medium including, but not limited to, conventionaltelephone lines, a cellular communication structure, the internet, orradio communication systems. The central monitoring unit 10 receives theevent signal and broadcasts a radio dispatch message over a radiofrequency 18. Alternatively, the central monitoring unit 10 may transmitthe dispatch message to a telephone 15, a PDA 16, a computer 17, or anyother suitable device.

In an exemplary embodiment, each remote monitoring device 11 is adaptedto detect event conditions, such as alarms, intrusions, breakdowns, orthe like. Upon detection of an event, the remote monitoring device 11then contacts the central monitoring unit 10.

The remote monitoring devices 11 may be implemented using a variety ofdevices. In operation, the remote monitoring device 11 may beimplemented simply with a sensor and a dialer. For example, and notlimitation, a simple sensor may include a panic button. In such anembodiment, the dialer would automatically dial the phone number of thecentral monitoring unit when an operator presses the panic button.Alternatively, simple sensors may include intrusion sensors, motionsensors, contact sensors, temperature sensors, infrared sensors,microware sensors, acoustic sensor, multi-technology sensors, and thelike. Alternatively, the remote monitoring device may comprisesignificantly more features and may be adapted to detect a variety ofevents.

Upon detection of an event, the remote monitoring device 11 places acall to the central monitoring unit 10. The central monitoring unit 10receives the call and determines the origin of the call. The centralmonitoring unit 10 may determine the origin of the call using DNIS data,or other means for determining call origination. In an alternativeembodiment, the remote monitoring devices 11 may be configured toprovide a device code to the central monitoring unit 10. In such anembodiment, the central monitoring unit 10 may use the device code toidentify the event message originator.

During installation, each remote monitoring device 11 is associated withan installation location. The central monitoring unit 10 records thislocation so that it can identify the remote monitoring device 11 when itreceives an event signal. For example, the remote monitoring device 11may be associated with a telephone number so that the central monitoringunit 10 can recognize the remote monitoring device 11 when it receives acall from the telephone number associated with the remote monitoringdevice 11. Alternatively, during installation the remote monitoringdevice 11 may be associated with a device code instead of a telephonenumber.

Additionally, during installation, or any time thereafter, a dispatchmessage may be recorded and associated with the remote monitoring device11. Preferably, the dispatch message provided information about theevent, its location, and a desired response. For example, if the remotemonitoring device were installed with a motion sensor at 123 MainStreet, the recorded dispatch message might include the followinglanguage: “Security needed at 123 Main Street, please respond quickly.”Alternatively, the event message may request fire assistance,maintenance assistance, or any other required attention. When thecentral monitoring unit 10 detects a call from the remote monitoringdevice 11, it broadcasts the associated prerecorded dispatch message. Ina preferred embodiment, the message is broadcast over a radio frequency.In an exemplary embodiment of the present invention, the prerecordedmessages are stored in a message database and the database is accessedwhen an event signal is received.

In an alternative embodiment of the present invention, the prerecordeddispatch message may be recorded in the form of text. In such anembodiment, the text message is converted to audio using a text tospeech processor and is then broadcast over the radio frequency. In yetanother alternative embodiment of the present invention, the remotemonitoring device 11 may transmit a text message to the centralmonitoring unit 10. This text message may then be converted to audiousing a text to speech processor and transmitted over the radiofrequency.

In an exemplary embodiment of the present invention, the system may beprogrammed such that a dispatch message is only broadcast during certainhours. In such an embodiment, the system may determine that an eventsignal was received from a remote monitoring device 11 for which adispatch message should only be broadcast during a predetermined timeperiod. For example, it may be desirable to only broadcast the dispatchmessage at night or outside of normal business hours.

FIG. 2 is a schematic block diagram showing interconnections ofexemplary electronic components of the present invention. Those skilledin the art will recognize that FIG. 2 shows an exemplary system diagramand that the present invention may operate using various systemconfigurations. FIG. 2 is provided to illustrate an exemplaryconfiguration; however, the present invention is not intended to belimited to the exact configuration illustrated.

Those of skill in the art will recognize that FIG. 2 illustrates anexemplary central monitoring unit 10. In various embodiments, thepresent invention may or may not include remote monitoring devices 11,but in general it receives event messages from such devices.Accordingly, third party or preexisting remote monitoring units 11 maybe used in conjunction with the central monitoring unit 10 of thepresent invention. In general, any remote monitor device may be usedthat can send an event signal to the central monitoring unit 10.

The system preferably includes a central processing unit (CPU) 32. TheCPU 32 functions as the brains of the system by receiving informationfrom various peripherals and performing processing functions. While theCPU chip itself may be chosen from among any of a number of commerciallyavailable chips, it has been found that ARM Chip No. LPC2148 availablefrom Philips functions exceptionally well in the circuit of thisinvention.

The CPU 32 is coupled through an address port 33 to the address bus 34of the circuit and through a data port 36 to the data bus of 37 of thecircuit. As will be well understood by persons of ordinary skill in thisart, various peripheral circuitry such as a power source, a crystalclock oscillator, and the like, is also coupled to the CPU for normaloperation thereof. Such peripheral circuitry has been omitted from FIG.1 for clarity of understanding.

A watchdog timer 38 may be coupled to the CPU 32 and functions tomonitor the status of the CPU 32 and its related hardware and to resetthe CPU 32 in the event of an abnormal condition of the hardware. Thefunction of the watchdog timer 38, therefore, is to oversee thecondition of the CPU 32 and related chips and is a normal function ofmost CPU chips. In fact, in the Philips chip of the preferredembodiment, the watchdog timer is built into the CPU chip itself andfunctions transparently until an abnormal hardware or software conditionoccurs.

Also coupled to the CPU 32 through the address 34 and data 37 busses ofthe circuit is a clock/calendar 42 that maintains the current date andtime of day and that can make this information available to the CPU 32through the data bus 37 when desired.

A set of erasable programmable read-only memory (EPROM) chips 43 arecoupled to the CPU 32 through its data and address busses.Alternatively, FLASH memory, or any other suitable memory source may beused in place of the EPROM chips 43. Accordingly, the present inventionis not intended to be limited to EPROMs. Thus, while the presentdescription refers to EPROM chips, those of ordinary skill in the artwill recognize that the alternative memory devices fall within the scopeof the invention. The memory provided by these EPROM chips 43 is used tostore invariant information and data such as the software program thatcontrols the various functions of the system and the digitizedpre-programmed set of words and commands that can be accessed andbroadcast over a radio transmitter.

The system may also include random access memory (RAM) 44, which may beused to store changing or intermittent data during operation of the CPU32 and that also may be used to store user input data, such as customdigitized words or other commands input by the user of the system. Aswith the EPROM chips 43 and the clock/calendar 42, the RAM 44 is coupledto the CPU 32 through the address and data busses of the circuit. Asillustrated by the direction indicators 46, the data flow between thedata bus 37 and the RAM 44 may be in both directions such thatinformation can be both written to and read from the RAM duringoperation of the CPU 32. This is also true of the clock/calendar 42. Thedata and information stored in the EPROM chips 43, however, typicallyonly flow from the chips to the CPU 32.

An address decoder 47 may be coupled to the CPU 32, to the address bus34, and to various peripheral devices such as the EPROMs 43, theclock/calendar 42, the RAM 44, and other chips. In an exemplaryembodiment of the present invention, a programmable logic device, suchas the XCR3256 available from Xilinx may be used as the address decoder47. Upon receipt of a read or write instruction from the CPU 32, theaddress decoder 47 may determine from the address on the address bus 34which of the peripheral devices corresponds to the address and activatesthe corresponding device accordingly. The CPU 32 might, for example,instruct the address decoder 47 that it would like to retrieve the datastored in a particular address assigned to the RAM chip 44. The addressdecoder 47 would then read the prescribed address from the address bus34, decode the address to determine that it indeed resided in the RAMchip, and activate the RAM chip to output the contents of the specifiedaddress onto the data bus 37, where it can be used by the CPU 32 or byother peripheral devices coupled to the data bus 37.

An alarm processor 41 may be provided to receive event signalinformation from the remote monitoring devices 11, 12. In an exemplaryembodiment of the present invention, the alarm processor 41 detectscaller ID information and identifies which remote monitoring device 11,12 sent the event signal. The caller ID information may include, but isnot limited to, DNIS data, origination telephone number, originationname, origination company, or any other information associated with theorigination telephone number or device. For example, if the caller IDinformation matches the telephone number for remote monitoring device11, then the alarm processor 41 identifies that remote monitoring device11 initiated the event signal. The alarm processor 41 then places anappropriate message on the data bus to instruct the system to broadcasta message from remote monitoring device 11 and it places an appropriatemessage on the address bus to access the recorded message associatedwith remote monitoring device 11. The recorded message is then directedfrom the voice chip 43 to the transmitter 51 for broadcast.

The transmitter 51 may be a two-way radio transceiver, such as theVertex VX160 available from the Yaesu Corporation. Alternatively, manyother transmitters may be used. Additionally, for greater compatibility,the present invention may be provided without a transmitter 51. In suchan embodiment, it is preferable that cabling be provided so that a usermay connect a third party transmitter to the system. The transmitter ispreferably coupled to the CPU 32 and may be activated thereby totransmit verbal commands appropriate to a given alarm or othercondition. The transmitter 51 is preferably provided with an input 52for receiving information to be transmitted, an output 53 through whichsignals received from an external transmitter are available, a “push totalk” input 54 that, upon receipt of an appropriate signal, places theradio transceiver 51 in the transmit mode, and an antenna 56 over whichradio frequency signals are received and transmitted.

The input 52 and output 53 of the radio transceiver 51 are coupled tothe central processor data bus through a CODEC chip 57. The CODEC chip57 performs dual functions in the circuit illustrated in FIG. 2. In onemode, previously digitized voice commands may be retrieved from memoryby the central processor and made available to the CODEC chip 57 throughthe system data bus. The CODEC chip 57 then converts the digitized voicecommands back to their analog equivalents. These analog signals are thenpresented to the input 52 of the transmitter 51 for broadcast thereby.

In the second mode of operation of the CODEC chip 57, voice commandsthat are received by the transceiver 51 from a remote transmitter can beconveyed through the transceiver output 53 to the CODEC chip 57. TheCODEC chip 57 may then convert the analog signals to their digitizedequivalents and make these digitized equivalents available to thecentral processor through the data bus 37. The central processor maythen store such commands for later retrieval and use. This function ofthe system is useful for receiving user input words or commands tosupplement or enhance the list of commands stored in the system EPROM43.

In an exemplary embodiment of the present invention, the functionalityof the CODEC chip 57 may be performed by the VOICE chip 43. A VOICE chipsuch as the commercially available Winbond ISD15000 may be used in suchan embodiment.

The CPU 32 may also be coupled to the input 52 and output 53 of thetransceiver 51 through a Dual Tone Multi-Frequency (DTMF) Keypadencoder/decoder such as Chip Model No. MT88L85 available from theZarlink Corporation. The function of the DTMF 58 is similar to that ofthe CODEC chip 57 except that the DTMF 58 encodes and decodes standardtouch-tone keypad signals rather than verbal commands. In this way,digital information keyed into a remote radio transmitter and receivedby the transceiver 51 can be digitized and presented to the centralprocessor through the data bus 37. Likewise, predetermined digitizedkeypad data can be converted by the DTMF 58 to its analog tonalequivalent and transmitted over the transceiver 51 if desired. WhileDTMF type information is contemplated in the preferred embodiment, itwill be understood that virtually any type of control signals, such asFSK signals, can be recorded and stored in EPROM or RAM for transmissionby radio or other means. This capability is useful in the system forexternal programming of various functions of the system. For example, asecurity guard equipped with a two-way radio of the type having adigital keypad might transmit to the central processor a predeterminedsequence of keyed characters representing a preprogrammed command. Thecentral processor may then respond accordingly by, for example,announcing the time, temperature, alarm history, message playback,voicing zone schedules, or performing some other preselected function.

In exemplary embodiments of the present invention, the system may beprogrammed using a variety of programming methods. For example, and notlimitation, the system may be programmed using computer software, an LCDmenu via membrane, and/or DTMF codes received over a radio or atelephone. A computer or other device may connect to the system via USBport, serial port, Ethernet port, wireless port, or any other suitableconnection mechanism in order to access and program the system.

A busy channel detector 59 is coupled to the output 53 of transceiver 51and can be activated to inform the central processor through the databus as to whether the radio channel is busy, i.e. whether signals arebeing received from remote radio transmitter sources. This function isuseful to ensure against inadvertent transmission while the channel isbeing used by others. In this regard, a relay or solid state driver 61may be coupled to the central processor 32 and can be activated therebyto select the transmit mode of the transmitter 51 by an appropriatesignal at the push to talk input 54.

A battery 62 provides power for operating the system of this inventionand, when low, can be recharged by means of an internal or externalbattery charger 63. The battery and battery charger are coupled to thecentral processor through the ADC 49. In this way, the central processorcan check the status of the battery and perform appropriate functionssuch as announcing its voltage, announcing that a charge is needed,shutting down the system to preserve the battery, or similar actions.

The CODEC chip 57, DTMF 58, busy channel detector 59, and relay driver61 can be selected by the central processor through the address decoder.The selected device can then read information made available by thecentral processor on the data bus or can place information on the databus for receipt by the central processor.

The system of the present invention as illustrated in FIG. 2 ispreferably programmed to place itself in a standby or quiescent modewhen there are no activated alarms or other signals to be processed.This is done to preserve battery power and to extend the life of theinternal battery to its maximum possible extent. In the quiescent modeof the system, most of the electronic devices such as the CPU 32, thememory chips 43, 44, the alarm processor 41, and the like, are placed ina standby mode in which they draw very little current. The system canthen be instructed to “wake up”, or activate, upon the occurrence ofanyone of a number of predetermined conditions such as an eventcondition, the activation of a sensor, the detection of a low battery,or simply at predetermined time intervals for housekeeping purposes. Thesystem is activated by means of either a reset or interrupt signalconveyed to the CPU 32.

In the preferred embodiment, the system may be instructed to “wake up”or activate upon the occurrence of five distinct conditions; namely,power on, power off, an event condition, the activation of an alarmsensor, to perform housekeeping functions, or at predetermined timeintervals to check the clock and implement a user input schedule for theevent conditions. The occurrence of any of these events may reset thecentral processor and cause it to perform a number of functionsdepending upon the nature of the event.

The preferred embodiment is also provided with complete remote controlof the various alarm messages. Such control includes the capability toplayback previously broadcast messages, to record through a remote radiotransmitter a voice message to override a system default message, or tospecify any sequence of prerecorded words/messages that should bebroadcast in response to activation of any of the system events. All ofthese functions and more can be implemented remotely through commandsentered into the keypad of a remote radio transmitter.

FIG. 3 is a flow diagram illustrating an exemplary method of receivingan event signal and broadcasting a dispatch message in accordance withan exemplary embodiment of the present invention. As shown in FIG. 3, inan exemplary embodiment of the present invention, the central monitoringunit 10 may be adapted to receive an event message 80 from a remotemonitoring device 11. As stated above, the event message may be in theform of a telephone call or other message sent to the central monitoringunit 10. In a preferred embodiment, the event message comprises atelephone call to the central monitoring unit 10.

Upon receipt of the event message, the central monitoring unit 10 mayverify the validity of the event message 81. The validity of the eventmessage may be verified by comparing the caller ID data received with alist of telephone numbers for installed remote monitoring devices.Alternatively, the event message may be verified by assuring that theevent message was generated by an approved remote monitoring device 11or that the event code is a recognized event code.

Once the event message has been validated, the central monitoring unit10 may access a pre-recorded dispatch message 82. The dispatch messagecorresponds to the event message received and may contain informationassociated with the event and the location of the event. Thepre-recorded dispatch message may then be broadcast 83. Preferably thedispatch message is broadcast over a two-way radio system.Alternatively, the dispatch message may be broadcast over anyappropriate communication system in order to inform a desired recipientof the presence of the event.

In an alternative embodiment, the present invention may be configuredsuch that multiple event messages may be associated with a single remotemonitor device. In such an embodiment, the remote monitor device maytransfer DTMF codes (touchtone codes) to the central monitoring unit toidentify a particular event associated with the remote monitor device.For example, and not limitation, a remote monitor device may beinstalled with sensors that detect three events: 1) a security breach,2) a fire, and 3) a computer system error. Further, the system may beset up so that a security message is broadcast on a police band radiowhen the security breach is detected, a fire message is broadcast on afire protection band radio when a fire is detected, and a computersupport message is broadcast on a computer support radio system when acomputer system error is detected. In operation, the remote monitoringdevice places a call to the central monitor unit when an event isdetected. The central monitor unit may then determine the location ofthe event based on DNIS information. When the central monitor unitanswers the call, it may then receive DTMF codes from the remote monitordevice to determine the event that occurred. The central monitor unitmay then access the appropriate dispatch message from a dispatch messagedatabase and broadcast the message on the appropriate communicationsystem.

The system has been described herein in terms of a preferred embodiment.It will be obvious to those of ordinary skill in the art, however, thatmany variations might be made to the illustrated embodiment within thescope of the invention. For example, while the invention has beenillustrated as broadcasting voiced commands over a two-way radio, itwould be a simple matter to have the system dial a telephone number andbroadcast the commands over telephone lines or other transmission means.The words “transmitter” and “transmission” as used herein shouldtherefore be understood to refer to any means of transmitting verbal orcoded messages to remote locations. In addition, a cellular telephonemight be activated instead of the two-way radio of the preferredembodiment such that the system could make cellular phone calls andstill be self-contained. Finally, while the preferred embodimentcommunicates with the outside world via spoken messages, it will beclear that other types of coded messages or information could besubstituted for the spoken messages of the preferred embodiment withsimilar results. These and numerous other additions, deletions, andmodifications might well be made to the preferred embodiment withoutdeparting from the spirit and scope of the invention as set forth in theclaims.

1. A monitoring system comprising: a first remote monitoring device fordetecting a first event condition and transmitting a first event signal;a second remote monitoring device for detecting a second event conditionand transmitting a second event signal; a central monitoring unit, incommunication with the first remote monitoring device and the secondremote monitoring device, for receiving the first event signal and thesecond event signal, the central monitoring unit being adapted tobroadcast a first prerecorded radio dispatch message when the centralmonitoring unit receives the first event signal and to broadcast asecond prerecorded radio dispatch message when the central monitoringunit receives the second event signal.
 2. The monitoring system of claim1, wherein the first remote monitoring device and the central monitoringunit communicate over a telephone line.
 3. The monitoring system ofclaim 1, wherein transmitting a first event signal comprises dialing apredetermined telephone number.
 4. The monitoring system of claim 1,wherein the central monitoring unit detects reception of the first eventsignal by detecting a signal identifying the number that originated atelephone call to the central monitoring unit.
 5. The monitoring systemof claim 1, wherein the central monitoring unit detects reception of thefirst event signal using caller ID information.
 6. The monitoring systemof claim 1, wherein first remote monitoring device and the centralmonitoring unit communicate over a cellular telephone network.
 7. Themonitoring system of claim 1, wherein the event conditions are triggeredby one or more sensors in communication with the remote monitoringdevices.
 8. The monitoring system of claim 7, wherein the event signalscomprise information regarding which of the one or more sensorstriggered the event condition.
 9. The monitoring system of claim 1,wherein the central monitoring unit comprises: an alarm processor forreceiving the first event signal and identifying the first remotemonitoring device; an audio file storage device for storing a pluralityof prerecorded dispatch messages, wherein a first prerecorded dispatchmessage is associated with the first event signal; and a transmitter forbroadcasting the first prerecorded dispatch message when the alarmprocessor receives the first event signal.
 10. The monitoring system ofclaim 1, wherein the central monitoring unit only broadcasts the firstprerecorded radio dispatch message if the central monitoring unitreceives the first event signal during a predetermined time period. 11.A monitoring system comprising: a first remote monitoring device fordetecting a first event condition and transmitting a first event signal;a second remote monitoring device for detecting a second event conditionand transmitting a second event signal; a central monitoring unit, incommunication with the first remote monitoring device and the secondremote monitoring device, for receiving the first event signal and thesecond event signal, the central monitoring unit being adapted tobroadcast a first message over a first radio frequency when the centralmonitoring unit receives the first event signal and to broadcast asecond message over a second radio frequency when the central monitoringunit receives the second event signal.
 12. The monitoring system ofclaim 11, wherein the message broadcast over the first radio frequencyand the message broadcast over the second radio frequency are the samemessage.
 13. The monitoring system of claim 13, wherein the messagebroadcast over the first radio frequency is a first pre-recorded messageassociated with the first event signal.
 14. The monitoring system ofclaim 13, wherein the message broadcast over the second radio frequencyis a second pre-recorded message associated with the second eventsignal.
 15. A method for broadcasting a dispatch message comprising thesteps of: receiving a first event signal from a first remote monitoringdevice at a central monitoring unit; identifying the first remotemonitoring device as the originator of the first event signal; accessinga first prerecorded dispatch message, associated with the first eventsignal, stored in the central monitoring unit; and transmitting thefirst prerecorded dispatch message using a transmitter in the centralmonitoring unit.
 16. The method of claim 15, further comprising thesteps of: receiving a second event signal from a second remotemonitoring device at the central monitoring unit; identifying the secondremote monitoring device as the originator of the second event signal;accessing a second prerecorded dispatch message, associated with thesecond event signal, and stored in the central monitoring unit; andtransmitting the second prerecorded dispatch message using a transmitterin the central monitoring unit.
 17. The method of claim 16, wherein thefirst event signal is associated with a first event condition and thesecond event signal is associated with a second event condition.
 18. Themethod of claim 17, wherein the event conditions are triggered by one ormore sensors in communication with the remote monitoring devices. 19.The monitoring system of claim 18, wherein the event signals compriseinformation regarding which of the one or more sensors has triggered theevent condition.
 20. The method of claim 18, wherein at least one of theone or more sensors in communication with the remote monitoring devicesis a motion detector.